Various braided medical devices are used for treating various conditions in a patient. In certain circumstances, it may be necessary to use such devices for occlusion of a patient's lumen, vessel, chamber, channel, hole, or cavity. When delivering or implanting such devices into the patient's body it is critical that the braided device is sufficiently flexible for safe delivery by a delivery device such as a catheter to a target site in the patient. The ease of operation by which the medical device can be delivered is crucial from several aspects such as requirements to comply with time limits for quick treatment or overall safe positioning or maneuvering of the device at the target site.
Issues with some prior art solutions are that the braided devices are not sufficiently flexible, and/or that a large force is required to manipulate the device, for example due to too high stiffness of the braided mesh of the device. This may lead to a difficult delivery of the braided device through for example a catheter. For braided devices having an expanded and a collapsed shape configuration the large force needed to collapse the device from the relaxed expanded state may lead to difficulties to pull the device into for example the delivery sheath of the catheter. Also, due to this force, making these braided device less flexible, the friction between the device and the catheter will be too high in order to easily move and manipulate the device in the catheter, for both movement to pull and to push the device in the catheter. Thus, there is a need for a braided device which allows a secure deployment in the patient.
Insufficient flexibility of some braided devices known in the art may also make the positioning of the device in the patient's body more difficult, for example, by the inability for the device to adapt to the unique anatomy of the target site. Further, a stiff device may lead to injury at the target site, for example to soft tissues in contact with the device. There is accordingly a need for a braided device which adjusts for differences in the anatomies between patients. Further an inflexible device may cause embolies, which could be transported to organs such as the brain and cause blood clots. This appears in particular to be the case with some devices having ends clamped together. In particular it may be an issue to have a distal end having a structure protruding into an arterial (high blood pressure) blood stream leading to vital organs, such as the brain. One issue are protruding threaded clamps keeping together a bundle of strands, such as described in WO99/12478.
WO2008/040555 discloses a braided occlusion device having folded sections in two or more layers for positioning in an opening. Sections at the distal portion of the device are back-bent towards the proximal portion to contact the tissue of the wall having the opening to be occluded. The folded sections cause the device to exhibit a substantial amount of wires to be deformed when compressing the device, hence increasing the force necessary to compress the device and the cross-section of the compressed device.
US2005/0283962 discloses a method of manufacturing a device of a tubular braiding. An issue with tubular braidings as disclosed in US2005/0283962 is insufficient stability that may lead to dislocation of the device from the implanted site.
An issue with prior art braided devices is that catheters with too large cross-section are required, as the devices take up large space even when in the collapsed state. Some regions of the body may thus only be reached with difficulty by such devices requiring large diameter catheters.
A further disadvantage with prior art is that some devices designed to be flexible may not have the sufficient retention force to withstand external forces.
Above disadvantages and issues may have dire consequences for the patient and the health care system. Patient risk may be increased.
Hence, an improved implant would be advantageous and in particular allowing for increased flexibility, cost-effectiveness, and/or patient safety would be advantageous. Also, and a method for manufacturing such medical implant would be advantageous.